#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
int main()
{
    int ret = fork();
    if(ret < 0)
    {
        perror("fork");
        return 1;
    }
    else if(ret == 0)
    { //child
        printf("I am child : %d!, ret: %d\n", getpid(), ret);
    }
    else
    { //father
        printf("I am father : %d!, ret: %d\n", getpid(), ret);
    }
    sleep(1);
    return 0;
}